Adolescent pregnancy is a significant public health and social challenge, with around 90% of these pregnancies occurring in low-and middle-income countries. This study aims to determine the prevalence of adolescent pregnancy and its associated factors among older adolescents in Mpigi district, Uganda. A community-based cross-sectional study was conducted from September to October 2024 among adolescent girls aged 15 to 19 years in Mpigi district, Uganda. Participants were selected using a multistage sampling approach from 12 villages within the district. The data was collected using an interviewer-administered structured questionnaire, assisted by four data collectors. Descriptive statistics were employed to determine the prevalence of adolescent pregnancy, while inferential statistics with bivariate and multivariable logistic regression analysis were conducted to identify associated factors with adolescent pregnancy. Out of 482 participants, 104 (21.6%) have experienced adolescent pregnancy. Significant factors associated with adolescent pregnancy were age (AOR: 1.40, 95% CI: 1.02-1.93, p=0.039), marital status (married before 18 years) (AOR: 69.24, 95% CI: 8.19-585.48, p